Finding Book Reviews  

For book reviews (both scholarly and non-scholarly) of books published in last 10-20 years:

Academic Search Complete 
Searches for book reviews in magazines and journals.  A good first stop when looking for reviews of either scholarly or popular books.

Book Review Index
A comprehensive list of book reviews for both popular and scholarly works. To find a review, choose the appropriate part of the set based on the book's publication date, then look under the author's name. 
REF/INDEX TABLES

Book Review Digest
Identifies reviews that appeared in magazines, journals, and newspapers.  Annual volumes list reviews under the author's name.  Each entry includes a summary of the book's contents, excerpts from some reviews and citations for complete reviews. There is a title index in the back of each volume. (NOTE:  Be sure to check the year of publication as well as the next two years for late-appearing reviews.) 
REF/INDEX TABLES

JSTOR
Good for reviews of scholarly books. Use the "Advanced Search" function to limit "Type: Review." Does not search for recently published book reviews. More information.

Project Muse
The "Advanced Search" allows you to limit the document "By Type." Choose "Review." Best for reviews of scholarly works.

Literature Resource Center
Search for the author, then click on "Literary Criticism, Articles, & Work Overviews." Book reviews are included in that section.

Books In Print
Records describe in-print, out-of-print, and forthcoming books, audios, and videos from North American publishers and U.S. distributors and wholesalers. Some descriptions include book reviews.

Try also, specific subject databases.